Cronulla's record against top-eight sides is well publicised, having not claimed a big scalp since August 2019 even while making last year's finals.

The Sharks led 18-4 against the Roosters on Saturday night before falling over, in a cruel hit to Morris as he fights to earn another contract at the club.

It comes after they also blew a chance to take Canberra to golden point on the siren three weeks ago, scoring two tries each but losing 12-10.

But Morris maintains his side have not forgotten how to win, and nor is their big-game record a talking point within the club.

"We don't talk about it at all. You guys only talk about the (Sharks' record against) bigger teams," Morris said.

"There are a lots of other teams in the competition who have struggles beating the teams at the top.

"The Roosters are a quality outfit, they have quality players right through that team.

"I don't think it's a mental game with how we played at the back of that game.

"I know they had players out but we had more adversity today, we lost Wade Graham and Josh Dugan (to concussions)."

The blows to Graham and Dugan, meanwhile, shape as significant concerns.

Graham's heavy knock was his second concussion in 15 days, while Dugan also failed a HIA last week.

The pair only have a six-day turnaround to be fit to face Newcastle on Friday evening, placing them in serious doubt.

"We just can't get through a game of footy without losing anyone," Morris said.

"But that's 2021, you have to be good at adjusting and adapting ...

"(Wade) seemed okay with how he was talking to the team then. But he copped a fair whack.

"Duges was assessed at halftime and was struggling as well. It's not great on that front, we'll have to see how they go during the week."

Australian Associated Press